Carbonized wood-based materials

Abstract

A method of carbonizing fabricated wood-based materials, such as wood composition board, is disclosed. Fabricated wood-based material is used as a precursor material, which is carbonized under controlled temperature and atmosphere conditions to produce a porous carbon product having substantially the same cellular structure as the precursor fabricated wood-based material. The porous carbonized product may be used for various applications such as filters, fuel cell gas separators, and battery electrodes, or may be further processed to form carbon-polymer or carbon-carbon composites. The carbonized product may also be converted to a ceramic such as silicon carbide. Additional processing may be used to form ceramic-metal or ceramic-ceramic composites.

What is claimed is:  
     
         1 . A method of making a carbon-containing article, the method comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material; and    recovering the carbonized material.    
     
     
         2 . The method of  claim 1 , wherein the fabricated wood-based material comprises particleboard, fiberboard and/or plywood.  
     
     
         3 . The method of  claim 1 , wherein the fabricated wood-based material comprises a fabric.  
     
     
         4 . The method of  claim 1 , wherein the fabricated wood-based material has a length of greater than about 1 inch.  
     
     
         5 . The method of  claim 4 , where the fabricated wood-based material has a width of at least about 0.5 inch.  
     
     
         6 . The method of  claim 5 , wherein the fabricated wood-based material has a height of at least about 0.1 inch.  
     
     
         7 . The method of  claim 1 , further comprising cutting the fabricated wood-based material to shape prior to heating.  
     
     
         8 . The method of  claim 1 , further comprising machining the fabricated wood-based material to shape prior to heating.  
     
     
         9 . The method of  claim 1 , further comprising pressing the fabricated wood-based material to shape prior to heating.  
     
     
         10 . The method of  claim 1 , wherein the fabricated wood-based material is heated in an inert atmosphere.  
     
     
         11 . The method of  claim 10 , wherein the inert atmosphere comprises nitrogen.  
     
     
         12 . The method of  claim 1 , wherein the fabricated wood-based material is heated at substantially atmospheric pressure.  
     
     
         13 . The method of  claim 1 , wherein the fabricated wood-based material is heated to a temperature of at least about 300° C.  
     
     
         14 . The method of  claim 13 , wherein the fabricated wood-based material is heated to a temperature of less than about 1500° C.  
     
     
         15 . The method of  claim 1 , wherein the fabricated wood-based material is heated to a temperature of from about 400 to about 1000° C.  
     
     
         16 . The method of  claim 1 , wherein the fabricated wood-based material is heated at a heat-up rate of less than about 100° C./hour.  
     
     
         17 . The method of  claim 16 , wherein the heat-up rate is from about 1 to about 50° C./hour.  
     
     
         18 . The method of  claim 1 , wherein the fabricated wood-based material is heated at a rate of less than about 20° C./hour during at least a portion of the heating.  
     
     
         19 . The method of  claim 1 , wherein the carbonized material comprises graphite.  
     
     
         20 . The method of  claim 19 , wherein the carbonized material is converted to graphite by heating to a temperature of at least about 2000° C.  
     
     
         21 . The method of  claim 1 , further comprising shaping the carbonized material.  
     
     
         22 . The method of  claim 21 , wherein the carbonized material is shaped by cutting.  
     
     
         23 . The method of  claim 22 , wherein the cutting comprises a process selected from the group consisting of sawing, drilling, routing, milling, turning, grinding and sanding.  
     
     
         24 . The method of  claim 1 , further comprising converting at least a portion of the carbonized material to activated carbon.  
     
     
         25 . The method of  claim 24 , wherein the conversion to activated carbon is performed in a carbon dioxide-containing atmosphere at a temperature of from about 600 to about 1000° C.  
     
     
         26 . The method of  claim 1 , further comprising at least partially filling pores of the carbonized material with a metal.  
     
     
         27 . The method of  claim 1 , further comprising at least partially filling pores of the carbonized material with a polymer.  
     
     
         28 . The method of  claim 27 , further comprising at least partially converting the polymer to carbon.  
     
     
         29 . The method of  claim 28 , wherein the polymer comprises a phenolic resin.  
     
     
         30 . The method of  claim 1 , further comprising at least partially converting the carbonized wood to a ceramic.  
     
     
         31 . The method of  claim 30 , wherein the ceramic comprises silicon carbide.  
     
     
         32 . The method of  claim 30 , further comprising at least partially filling pores of the ceramic with a metal.  
     
     
         33 . The method of  claim 30 , further comprising at least partially filling pores of the ceramic with a ceramic.  
     
     
         34 . A carbonized article consisting essentially of carbon having a porous cellular structure corresponding to the cellular structure of fabricated wood-based material.  
     
     
         35 . The article of  claim 34 , wherein the fabricated wood-based material comprises particleboard, fiberboard and/or plywood.  
     
     
         36 . The article of  claim 34 , wherein the carbonized article has at least one dimension greater than about 1 inch.  
     
     
         37 . The article of  claim 34 , wherein the carbonized article is cut to shape.  
     
     
         38 . A method of making a carbon-polymer composite comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material;    cooling the carbonized material; and    at least partially filling pores of the carbonized material with a polymer.    
     
     
         39 . The method of  claim 38 , wherein the pores are at least partially filled with the polymer by infiltrating the pores with a polymeric fluid and curing the fluid.  
     
     
         40 . The method of  claim 38 , wherein the polymer is selected from the group consisting of epoxies, phenolics and pitch.  
     
     
         41 . A method of making a carbon-metal composite comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material; and    at least partially filling pores of the carbonized material with metal.    
     
     
         42 . A method of making a carbon-carbon composite comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material;    cooling the carbonized material;    at least partially infiltrating pores of the carbonized material with a carbon-forming material; and    converting at least part of the carbon-forming material to carbon.    
     
     
         43 . The method of  claim 42 , wherein the carbon-forming material comprises a phenolic resin which is at least partially converted to carbon by heating.  
     
     
         44 . A method of forming a ceramic-containing material comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material;    cooling the carbonized material; and    converting at least part of the carbonized material to a ceramic.    
     
     
         45 . The method of  claim 44 , wherein at least part of the carbonized material is converted to silicon carbide by reacting the carbon with silicon.  
     
     
         46 . A method of forming a ceramic-containing material comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material;    cooling the carbonized material; and    converting at least part of the carbonized material to a ceramic.    
     
     
         47 . A method of making a ceramic-ceramic composite comprising: 
 providing a fabricated wood-based material comprising a cellular structure;    heating the fabricated wood-based material in a substantially non-oxidizing atmosphere to a sufficient temperature at a sufficiently slow heat-up rate to carbonize the fabricated wood-based material while substantially maintaining the cellular structure of the fabricated wood-based material;    cooling the carbonized material;    converting at least part of the carbonized material to a first ceramic; and    at least partially filling pores of the ceramic with a second ceramic.    
     
     
         48 . The method of  claim 47 , wherein the first ceramic is of different composition from the second ceramic.  
     
     
         49 . A carbon-polymer composite article comprising: 
 a carbonized fabricated wood-based material comprising a porous cellular structure; and    a polymer at least partially filling the pores of the carbonized fabricated wood-based material.    
     
     
         50 . A carbon-carbon composite article comprising: 
 a carbonized fabricated wood-based material comprising a porous cellular structure; and    carbon at least partially filling the pores of the carbonized fabricated wood-based material.    
     
     
         51 . A carbon-metal composite article comprising: 
 a carbonized fabricated wood-based material comprising a porous cellular structure; and    a metal at least partially filling the pores of the carbonized fabricated wood-based material.    
     
     
         52 . A porous ceramic-containing material comprising ceramic having a porous cellular structure corresponding to a cellular structure of fabricated wood-based material.  
     
     
         53 . A ceramic-metal composite article comprising: 
 a ceramic having a porous cellular structure corresponding to the cellular structure of fabricated wood-based material; and    metal at least partially filling the pores of the ceramic.    
     
     
         54 . A ceramic-ceramic composite article comprising: 
 a first ceramic having a porous cellular structure corresponding to the cellular structure of fabricated wood-based material; and    a second ceramic at least partially filling the pores of the first ceramic.